Means for making shoe lasts

ABSTRACT

Apparatus for making shoe lasts. Electrical control signals which are proportional to the surface configuration of a shoe last model are derived and stored. Shoe last shaping machinery comprising a blank of suitable material and suitable cutting surfaces are moved relative to each other responsive to the stored electrical control signals.

I Unlted States Patent [151 3,674,063 Klingbeil 1451 July 4, 1972 s41 MEANS FOR MAKING SHOE LASTS 2,819,741 l/1958 Clausing ..142/15 x 2,828,673 I 4/1958 CampbelL. ..90/62 X [72] y 'l' 'L 8939 45th 2,887,638 5/1959 Cail etal ..90/13 c 3mm, 3,143,901 8/1964 Bawtinheimer... ...77/s BB [22] Fil d; A 13, 1969 3,269,233 8/1966 Lothmann ..82/14 2,410,295 10/1946 Kuehl et al .,....318/39 [21] Appl. No.: 849,832

Primary Examiner-Leonidas Vlachos s21 u.s.c1 ..142/1,142/13, 142/15, i"" s'egel 82/14 C [51] Int. Cl ..B23b 3/28 {57] ABSTRACT [58] Field 61 Search ..142/13, 15, 10, 11,30; 82/14, Apparatus for making shoe lasts- Electrical. control signals 2 14 90 1339 9 which are proportional to'the surface configuration of a shoe last model are derived and stored. Shoe last shaping machin- [56] References Cited ery comprising a blank 'of suitable material and suitable cutting surfaces are moved relative to each other responsive to UNITED STATES PATENTS the stored electrical control signals.

2,537,770 1/1951 Livingston et al. ....82/l4 B 1 Claim, 1 Drawing Figure ROTAT/ONAL /6 /9 DR/l E I I RAAD our MEMORY SENS/1V6 DEV/CE oswcs MEANS TRANS- CONVERTER DUCER MEANS MECHANICAL TRANSMISS/UA/ MEANS PATENTEDJUL 4 I972 3mm T/O/VAL i DIP/V5 Rumour MEMORY SENSING DEV/CE- DEV/CE MEANS TRANS- V co/vv /ens/e DUCER MEANS MECHANICAL TRANSMISS/O/V MEANS WLLIAM C: KLVEE BACKGROUND OF THE INVENTION This invention relates to apparatus for making shoe lasts and, more particularly, to electronically controlled apparatus for carving shoe lasts to conform to the surface configuration of a shoe last model.

Classically, shoe lasts are made on a machine specifically designed for their production. Generally, these machines are complex and cumbersome mechanical devices which utilize common tracing principles to produce the desired form for the shoe last. A single last may be utilized in the production of several pairs of shoes. The last can be made for conventional or nonconventional shoes which are specifically designed for problem feet. While making a shoe from the last, it is subject to significant wear and tear limiting its useful lifetime, and the last must be replaced periodically.

Generally, the principles employed in a machine for making such a shoe last are similar to those employed in common tracing machines. In particular, a predetermined shaped model is utilized and its shape is copies for the shoe last. The Model is mounted and rotated about its longitudinal axis while a sensing device, commonly a type of finger or probe, abuts the surface of the model sensing its various surface configurations.

Mechanical transmission means are employed to follow the movement of the probe in order to sculpt the shoe last to conform to the shape of the traced model. Generally, the last is made from a blank comprising of wood or other suitable material which can be easily shaped by cutting and grinding surfaces. The motion of the probe is transmitted through common transmission means, which are well known to those skilled in the art, and causes the cutting and grinding surfaces to move relative to the blank in order to sculpt and shape it in accordance with the shape of the model. Generally, in the prior art, the wood blank is rotated about its longitudinal axis while the cutting and grinding surfaces are caused to move against the blank causing it to conform with the shape of the shoe last model.

Generally, one size model is utilized for the production of a plurality of different sized show lasts by making adjustments in the machinery which produces the desired size shoe lasts. These adjustments are made manually and must be accomplished prior to the making of the shoe last. Unfortunately, the economy measure of using a single size model for several sizes of shoe lasts may result in the production of erroneously sized lasts.

The prior art method and apparatus for the manufacture of shoe lasts as described above has significant problems. lnitially, the model must be carefully and accurately made and commonly is fabricated of maple wood which is hand carved. Significant time, effort, and expense are required to manufacture the model and, further, significant waste ofien occurs when imperfections are discovered in the model. The various sized models utilized for the production of shoe lasts require storage under conditions which insure the size of the model remains substantially unchanged during its storage period.

Since the mechanical probe abuts the model while tracing its surface configurations, it may cause significant undue wear and tear. This substantially impairs the durability of each model so that each may only be used for the production of several shoe lasts. Often, though, the model is not damaged enough to require its replacement, but does require manual repair. This manual repair can be both expensive and timeconsuming causing the production facilities to be in-efficiently halted while the model is being repaired.

As stated above, because of the problems inherent in the use of models, where possible, a single size model is used for the production of several sizes of lasts. For instance, a size 9 model may be used for the production of size 10, 11, and 12 shoe lasts. This can cause inaccurately sized lasts to be produced which cannot be tolerated in the shoe manufacturing industry.

The prior art method of making shoe lasts utilizes asingle model for the .production of a single last. The mechanical means required to simultaneously produce several lasts from a single model is too cumbersome and complex to be utilized in the industry. This one for one production relationship, though,

,is basically ineflicient when considering the above mentioned nificant retooling and additional costs for new and untestedmachinery. Therefore, prior proposed improvements have not found ready acceptance in the industry.

An object of the present invention is to provide improved apparatus for making shoe lasts.

Another object of the present invention is. to provide improved apparatus for making shoe lasts without requiring sifnificant change in the present machinery utilized in the industry.

Still another object of the present invention is to reduce the cost of making shoe lasts.

Another object of the present invenfion is to produce more accurately sized and shaped shoe lasts.

Still another object of the present invention is to increase the rate of production of shoe lasts.

Another object of the present invention is to reduce the wear of the equipment utilized for the production of shoe lasts.

7 Still another object of the present invention is to eliminate the storage problem indigenous to the use of the models.

Another object of the present invention is to provide apparatus which may simply and efiiciently produce a plurality of shoe lasts simultaneously.

Still another object of the present invention'is to reduce the manual labor required in the production of shoe lasts.

7 Another object of the present invention is to reduce the cost and time required in the preparation of models for making shoe lasts.

Other objects of the present invention will become more readily apparent from the following description of the invention.

SUMMARY vention, the surface configuration of a shoe last model is traced by sensing means, and the information derived therefrom is converted and stored electronically.

Electrical signals generated, in accordance with the princi-. ples of the present invention, are proportional to shape of the physical model which is utilized and stored in the prior art. Consequently, the storage problem encountered in the prior art is eliminated by storing electrical signals rather than physical models. It may certainly be appreciated that electrical signals are more efficiently and compactly stored than that of physical models. Further, by utilizing electrical signals to provide the surface information to be followed, the wear problem encountered by using prior art models is eliminated.

In accordance with the principles of the present invention, a model need be traced only once in order to provide a permanent record from which shoe lasts can be made. As another feature of the present invention, the model to be traced may be made of paraffin or other malleable material which is more easily shaped and much less costly than maple wood. Since the model is only to be utilized once, its durability is relatively unimportant and significant cost savings can be realized by employing the principles of the present invention where the model need only be used once.

In accordance with the principles of the present invention, a bar made of a durable material which, for instance, might be steel or some other alloy, is mounted where I the model is mounted in the prior art machinery. A sensing device similar to that used in the prior art for tracing is now moved by the stored electrical signals and abuts against the bar causing it to follow the movement of the sensing device. The movement of the bar is directly transmitted causing the blank to move in accordance with the stored electrical signals. The blank abuts and is shaped by a series of cutting and grinding surfaces much in the same fashion as that accomplished in the prior art. Therefore, as another feature of the present invention, the same machinery that has been used in the industry may be used with the present invention allowing the advantages to.be realized thereby without significant retooling and new machinery costs.

In accordance with the principles of the present invention, the electrical signals may be simultaneously utilized by several shoe last manufacturing machines without the attendant complex mechanical linkages required in the prior art. The simultaneous transmission of electrical signals to several independent receivers may easily be accomplished by well-known methods and, this simultaneous manufacturing process may significantly lower the cost to manufacture each shoe last. It is readily apparent that the principles of the present invention significantly reduce the time and labor attendant the prior art manufacturing process.

As another feature of the present invention, more accurately sized lasts may be produced. In the prior art, a size l model was used for making a size 9, l0, and 11 lasts while, in the present-invention, since the problems associated with the use of physical models have been eliminated, information may readily be stored corresponding to the specific size of the shoe last to be produced.

It may readily be appreciated that, in accordance with the principles of the present invention, the significant problems attendant the manufacture of shoe lasts with prior art apparatus have significantly been reduced. In particular, the storage, expense, labor, and efficiency problems have been remedied without requiring significant retooling of new machinery.

IN THE DRAWINGS The FIGURE is a block diagram illustrating the principles of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT A model is mounted on a bar 11 and rotated about its longitudinal axis by a rotational drive 12 driving bar 11 through suitable direct transmission means 13. Transmission means 13 may be a type of well-known gearing or other type of transmission system, such as hydraulic. The bar 11 is fixably attached between transmission device 13 and a surface or wall 14 and rotates about its longitudinal axis also causing model 10 to rotate.

As discussed above, model 10 may be made of material which is less durable than that required with prior art shoe last manufacturing machinery. in particular, paraffin or some other suitable material may be utilized in fabricating mode 10. While model 10 rotates, sensing device 16 abuts against it and iscaused to move generating singnals in accordance with its motion. In order to trace the various surface configurations of the entire model, sensing device 16 is attached to a threaded mechanism 17 which is engaged with the moves along threaded rod 18. Threaded rod 18 is caused to rotate about its longitudinal axis as is rod 11. Transmission device 19 transmits the motion of rotational drive 12 to rod 18 causing it to turn and, in turn, causing sensing device 16 to move along the length of model 10.

Electrical signals are produced by probe 16 and transmitted to sensing means 21. Sensing means 21 converts its received signals to those suitable for permanent storage which, for instance, may be stored in memory device 22. Conventional storage techniques may be uu'lized with the present invention, and the information provided by sensing means 21 may be stored on tapes, disks, drum or other suitable memory devices. Memory device 22 supplies its information through readout device 23 which is associated with the particular type of memory utilized. If memory device 22 were a series of drums, then readout device 23 would comprise a series of read heads while a series of write heads would be associated with memory device 22 in order to place the information from sensing means 21 on the drum. Other well-known conventional storage and readout devices may be utilized in accordance with the principles of the present invention, such as punch tape and print out devices.

The output of readout device 23 is supplied to converter 24 which concerts its received electrical signals to a form suitable for activating transducer means 26. The output of transducer means 26 is mechanical and is responsive to its received electrical signals. Mechanical transmission means 27 are employed to convert the output of transducer means 26 to a form suitable for use with the present invention. Converter means 24 are well known in the art and, for instance, convert the received electrical signals to those which may activate transducer means 26. Transmission device 27 may be hydraulic and suitable hydraulic transducer means can be employed where required.

The output of transmission means 27 causes probe 28 to move correspondingly. This is accomplished in any suitable and conventional manner, as, for example, through the medium of an hydraulic control 30. It will be understood by those skilled in the art to which the present invention pertains while the probe 28 is illustrated as if it will move vertically up and down in the plane of the paper, it is mounted in a horizontal plane, and the hydraulic control 30 causes the probe 28 to move in and out of the plane of the paper against a bar 29. The bar 29 abutsthe probe 28 as it is moved thereby in accordance with the output transmission means 27. The bar 29 may be made of highly polished steel or another suitable alloy specifically designed for long life, durability, and an absolute minimum of friction. The hydraulic control 30 comprises a threaded device 31 which is engaged by and caused to move along a threaded rod 32, in a manner similar to the sensing device 16 and the threaded mechanism 17.

Synchronization means, well known to those skilled in the art, are provided in order to insure that probe 28 moves bar 29 so as to follow the pattern of model 10. This synchronization information is stored in memory device 22 when model 10 is traced by sensing device 16. As the bar 29 is moved in and out of the plane of the paper by the motion of probe 28, the motion of the latter being determined by the hydraulic control 30, transmission means 23, which may be of any suitable and conventional construction, are employed to transmit the motion of the bar 29 to the blank 34 causing it to move and be shaped in accordance with the electrical information stored in memory device 22 and conform to the shape of model 10. Blank 34 may be made of wood or any other suitable material which will easily be shaped and contoured when it abuts against suitable cutting and grinding surfaces (not shown). The cutting and grinding surfaces are not illustrated, because they are conventional, and anyone skilled in the art to which the present invention pertains will be familiar with the cutting and grinding surfaces utilized to form the blank 34. At this point, it is to be understood that the blank 34, like the probe 28, and, thus, the bar 29, will move in and out of the plane of the paper.

In the prior art, the model to be traced was mounted where the bar 29 of the present invention is mounted. The probe 28 replaces the sensing device used in the prior art which follow the surface contour of the mounted model. That is, in prior art devices, the mounted model rotated, and the sensing device was thus caused to move in and out of the plane of the paper in response to the various contours along the mounted model. The motion of prior art sensing device (located where probe 28 presently is) was transmitted through transmission means similar to those of the present invention in order to cause the grinding and cutting surfaces to move against the blank while shaping it to conform to the shape of the mounted model. In the present invention, the grinding and cutting surfaces are held substantially stationary while the blank moves thereagainst enabling the blank to be shaped to conform to the shape represented by the stored electrical signals in memory device 22 corresponding to the surface information of model 10.

Where appropriate, memory device 22 may simultaneously operate a plurality of probes 28 to move so as to cause a plurality of shoe lasts to be simultaneously sculpted. In particular, a plurality of read heads may be associated with memory device 22 so as to simultaneously read the surface contour information to a plurality of probe 28. Only one operator need be present while a number of lasts are simultaneously being manufactured. This represents significant savings in the production costs of show lasts.

While the above description sets forth a preferred embodiment of the present invention, it is to be understood that the present invention encompasses all modifications and changes obvious to those skilled in the art while practicing the present invention. To that end, this application is not to be construed as limiting the scope of protection to the specific embodiments set forth but merely construed as illustrative of the prin ciples of the present invention.

What is claimed is:

1. An apparatus for shaping a shoe last from a blank comprising;

a source of electrical control signals; a blank capable of being shaped to form a shoe last; means to shape said blank; means responsive to said control signals to cause said means I to shape said blank to move relative to said blank to form said shoe last; Said responsive means comprises;

transducer means; said transducermeans being caused to move responsive to said electrical control signals and; means to transmit the motion of said transducer means to said blank; said means to transmit the motion of said transducer means comprises; a bar coupled to said blank; a threaded device, said threaded device comprises a threaded rod; a probe coupled to said threaded device for movement with said threaded rod; control means for moving said probe radially with respect to said threaded rod, said probe engaging said bar, such that said bar is moved thereby, thereby moving said blank; grinding and cutting means rigidly held with respect to said blank, such that said blank is moved with respect thereto; transmission means to move said blank in accordance with the motion of said bar. 

1. An apparatus for shaping a shoe last from a blank comprising; a source of electrical control signals; a blank capable of being shaped to form a shoe last; means to shape said blank; means responsive to said control signals to cause said means to shape said blank to move relative to said blank to form said shoe last; Said responsive means comprises; transducer means; said transducer means being caused to move responsive to said electrical control signals and; means to transmit the motion of said transducer means to said blank; said means to transmit the motion of said transducer means comprises; a bar coupled to said blank; a threaded device, said threaded device comprises a threaded rod; a probe coupled to said threaded device for movement with said threaded rod; control means for moving said probe radially with respect to said threaded rod, said probe engaging said bar, such that said bar is moved thereby, thereby moving said blank; grinding and cutting means rigidly held with respect to said blank, such that said blank is moved with respect thereto; transmission means to move said blank in accordance with the motion of said bar. 